The invention relates to communication antennas and more specifically to plasma antennas energized with electrical parameters from distributed engine systems.
A plasma is a mixture of positively and negatively charged particles interacting with an electromagnetic field which dominates their motion and in which high temperatures may be reached. Plasma can be utilized as energy sources in many useful applications, such as antennas. In known plasma systems, gases are typically raised to a very high temperature by applying radio frequency power from an alternating current source to a coil encircling a working gas which is partially ionized. A magnetic field is useful for controlling the charged particles in a plasma by keeping them along field lines.
Conventional plasma antennas are of interest in communication systems since the frequency, pattern and magnitude of the radiated signals are proportional to the rate at which ions and electrons are displaced. The displacement and hence the radiated signal can be controlled by a number of factors including plasma density, tube geometry, gas type, current distribution, applied magnetic field and applied current. This allows the plasma antenna to be physically small, in comparison with traditional antennas.
A number of advanced and alternative propulsion concepts within the scientific and research community have been formulated for meeting the challenges of future aerospace applications. Many of these advanced propulsion concepts fall under the categories of chemical propulsion, nuclear thermal propulsion, and electric propulsion along with some hybrid concepts also. For the present invention, advanced electrical propulsion techniques are considered as the preferred arrangement of the invention due to the potential for closely controlling the properties of the “engine plasma discharge”. A number of novel and promising electronic propulsion techniques have been surveyed in the literature including Hall thrusters, ion thrusters, and pulsed plasma thrusters.
The idea of integrating plasma antenna concepts with distributed engine concepts shows potential for the development of integrated lightweight and agile antenna structures that can be reconfigured and “re-tuned” to meet the specifications of a variety of different real-time applications. For example, recent interest for the development of mini and micro UAV (Unmanned Aerial Vehicle) platforms for intelligence applications requires intensive analysis of size, weight, aperture, and power (SWAP) constraints in order to implement desired and enhanced capabilities on size-limited platforms. Integration of propulsion with avionics functions will lead to major breakthroughs towards the development of systems with these challenging SWAP constraints.
In addition, maturation of this new method for the development of plasma antennas will lead to future breakthroughs in antenna technologies. Some of these breakthroughs in technology will be realized by investigating and developing (inducing) additional electromagnetic propagation modes, for example, by reconfiguring the distributed electropropulsion system that is described in this disclosure to develop enhanced radar and communications capabilities over, for example, larger bandwidths.
For purposes of visualizing this integrated systems concept, FIG. 1 shows a NASA blended-wing prototype at 3% scale. In FIG. 1, the blended wing is shown at 101. In prototype of FIG. 1, the engines are shown at 100. The distributed engine system, 100, can be designed and implemented to function as a plasma antenna array. This type of plasma antenna implementation can be realized via developments in advanced joint propulsion and radiation propagation/scattering analysis and design techniques as disclosed in the description of the invention.